CHICAGO (CBS)–Payment apps like Venmo and Zelle offer a way to send and receive money at the click of a button, but how reliable are they?

With more than 15 million users and growing, online payment service “Cash App” is enjoying fast success. “Cash App” has emerged as a success story among the increasingly-crowded field of payment apps, doubling its active users in a year.

One of those customers, Porter Myrick of Chicago’s Pullman neighborhood, said he started using “Cash App” last year.

Myrick has been a long-time customer of finance apps like Zelle and Venmo, which he uses to transfer money to friends and family.

In December of last year, he tried a new one–“Cash App.”

After a $200 payment he was supposed to receive went missing, he started fumbling with the app to find answers.

“In the middle, there’s a tab that shows me the amount available, and then there’s a tab that says cash support,” Myrick said.

Myrick needed that support when he was unable to locate the $200 transfer, but answers didn’t come easy.

In mid-March, he followed all the prompts and submitted an inquiry to the customer service center–but he never heard back.

It turns out, his money was sitting in the app the whole time–he just couldn’t find it. Myrick only learned where his money was by playing with the app for weeks and getting to know its nuances.

A response from “Cash App” could have helped him find his money much sooner.

Myrick said a customer service response would have improved his experience on the app.

Financial analysts like Lamont Black, a professor at DePaul University, said fast-growing companies can experience growing pains.

Black said many new tech companies like “Cash App” lack the customer service support needed to parallel rapid growth.

One way to ensure you know where your money is going when use an app like “Cash App” is to test it out with a friend.

“If you download it and try to use it immediately without understanding where your money is, it might end up in the wrong account,” Black said.

A “Cash App” spokesperson told CBS 2, “Our goal is always to provide customers with fast and thoughtful customer support. Occasionally, as in this case, we fall short of that goal, and we’ll use it as an opportunity to learn and do better in the future.”

After Myrick’s debacle was finally resolved, “Cash App” managed to send him a customer service survey.

His opinion?

“I told them it needs improvement,” Myrick said.

Vince Gerasole