The most common reasons for payment rejection are:
Insufficient funds available on the account at the time of transfer
Daily transfer/payment limit exceeded
Our recommendation to prevent such problems:
Notify the PSU, paying particular attention to whether any of the above points apply to them.
If such rejections occur, we recommend first checking with the PSUs to see whether these two points are the cause.
If not, it could be an error, which we will gladly help you resolve - LINK