Pathetic service

I'm very disappointed in their service I tried calling them twice one 3rd of September wait in line long que I must add , just to get to number one and call to be cut of twice. I have emailed them no responds I have chatted to them online but they don't understand a robot can not answer your questions correctly. I have been with them over 5 months, so my payment showed error which was error on their system, I tried doing payment online but still showed error. Each time I got notification stating payment failed which they can see I tried to pay. Now they charge me interes of more 80%of the instalment how is that fair if I never removed my baking details? And there was money in my bank account? I'm not happy because I never missed a payment I need someone to investigate this. Payment is due the 26th but due to errors on your app I had to remove my card and add it again and paid the 3rd but had to pay amount of 245 extra not even a month later , this is pathetic service!!!