It is not possible to amend or cancel a payment after the day on which the payment was made.
If the payment needs to be allocated to another treatment provider then the following steps can be used:
1. The original payment will have to be refunded against the original treatment provider.
2. A new payment will have to be made recording the same amount of money but allocated to the correct treatment provider.
I hope this answers your question, if not then do please come back to us.