Suspended phone when paid

I took a contract with Nashua Mobile for my phone 3 years back & my daughter's phone onto the package, when Nashua mobile was handing over its business to Altech and Vodacom, I received communication to that effect & I never received information about the account payment details changes and I continued to pay the accnt as normal to the details that I added on my account as beneficiary with a scheduled payment, last 2 payments of Dec & Feb were paid as arranged, thinking that comms will be sent to us to inform us of the banking details changes, I then received the comms this month after the 2 payments were made that I have to pay the account directly to Vodacom. I then contacted Vodacom & told them of the issue, thinking that a handover like this, will have a takeover process in place of about 6 months for Nashua & Vodacom to do recons 4 customers like us, I then called Voda's customer service & was told that I should send the proof of payment that is my bank statement as I do not generate those because of the scheduled payment, i was also told to call Nashua mobile and inform them to refund & their fone goes to voicemail that says they will call u back. the phone is now suspended.