What is a Cash App Customer Service Phone Number? You might not have ever asked this question in your mind while sending and receiving the money to and from your contact on Cash App. As Square Cash App is a fast, safe, and reliable payment app; it seems quite irrelevant to think that any payment can fail on Cash App. But, if you get close to the ground level, you will find that ground reality is quite different. In recent years, cases of payment failure on Cash App have increased like never before. Issues like pending payments and incomplete Cash App transactions are rising to an alarming level. That's why it has become very important to learn how to contact Cash App customer service. But, before that, you must learn whether or not there is any Cash App customer care number or not where you can call and get assistance regarding pending payments and refunds.