Bad Service

I took a 6 months loan with Bruma finance and paid every month never missed any payment , my loan payment end date was the 30.04.2018 and now 25.05.2018 a full debit order went out of my bank account and Bruma finance cant explain why , I had to go to the bank and reverse this transaction. Today I'm getting an sms saying that my account is in arrears. Please can someone explain please explain this to me because I took a 6 months loan and paid that in full. Bruma finance service is bad customer service. Loan Reference Number – ********** 7