Abusive behaviour

Mix Telematics (Beamie) customer service sucks!! I have been using Beamie tracking for 7 years. Since covid started I have not been able to pay my the monthly premiums due to financial constraints. In April 2021- I have made arrangements to settle the arrears ( R1019.00) in 3 installments and started paying my monthly premiums. R350 was paid in May toward the outstanding balance but I still receive messages demanding the R1019 and threating to submit my name to credit bureau. I've sent proof of payments to their attorneys and finance department so many times with no response and the 350 I paid is not reflecting on the statement.