A Virginia borrower complained that after making a monthly mortgage payment via credit union electronic transfer the bank servicing the mortgage denied receiving payment despite two confirmation faxes from the credit union. In Texas, a borrower said a new servicer took over a loan, never sent a bill or responded to attempts to set up an account and make payments and then posted the home for foreclosure.

These are two of 3,910 complaints about mortgages sent to the Consumer Financial Protection Bureau in July 2016. Mortgages represent the third-biggest category of complaints to the CFPB, behind debt collection and credit reporting. As of April 1, 2016, CFPB's online complaint system had handled nearly 860,000 complaints since it opened 2011, of which mortgages accounted for more than 223,000.

Mortgage complaints spiked during the last recession and housing downturn before falling to about their current level. Now they may be heading up again. During the first quarter of 2016, average monthly mortgage complaints were up 21% from the same period a year earlier, according to the CFPB.

Rocke Andrews, president of the Plano, Texas-based National Association of Mortgage Brokers, says during the downturn complaints tended to be about brokers but more recently concern servicers. One reason is that pricing pressure is causing servicer consolidation and efforts to reduce costs, he says.

"What you see now is there are probably five servicers that handle 75% of all servicing," Andrews says. "To make it profitable, you have to scale it up and do as much as you can automated. As a result, as a consumer, more than likely you're going to wind up with one of those automated systems when you call in for information."

Andrews says consumers with a problem can increase chances of a successful resolution by bypassing the automated systems -- often by pressing the "0" key -- and asking the human rep to speak with a supervisor. If that doesn't work, try hanging up and calling back, he suggests.

Complaints come in many varieties, but since 2011, most (51%) are "problems when you are unable to pay," according to the CFPB. Next is "making payments," cited by 31%. Complaints about applying, signing the agreement and receiving a credit offer are all single digit percentages.

Some problems are caused by borrowers confusing the servicer, which collects payments and disburses taxes and insurance, and the holder of the mortgage note. Borrowers may be upset that a servicer won't approve skipping a payment, when the borrower has to approve that, Andrews says.

Another common problem regards partial payments. Sometimes, such as during foreclosure proceedings, the amount owed may change after a payment is mailed and before it is received. The borrower may think payment has been made, when in fact it's been disallowed as a partial payment. New rules require servicers to tell borrowers upfront whether they will accept partial payments may help this problem, Andrews says.

While nearly a quarter of a million complaints to regulators sounds like a lot, Marina Walsh, a vice president with the Washington, D.C.-based Mortgage Bankers Association, notes that problems are typically handled before reaching the CFPB, and the complaint count is modest compared to the number of borrowers. "There are approximately 50 million outstanding mortgages in the U.S. and many more customer escalations or complaints are tracked and logged, then resolved directly by the mortgage servicer," Walsh says.

Walsh said dedicated phone numbers, customer service-friendly websites and better call center monitoring is helping to improve borrowers' experiences with servicers. "On the technology side, servicers have woken up and realized that they need to go digital especially for millennial borrowers," Walsh says. "This means revamping websites to provide more capabilities, offering seamless mobile options and generally moving toward a self-service and self-monitoring model preferred by some many borrowers, particularly Millenials."