Bad business practices and really slow follow up.

I won on auction Bidorbuy a 35AH battery and waited 2 weeks for the the tracking numbers and details for the battery. I then emailed them without reply I then gave bad review on Bidorbuy then they woke up. Isaac says they sorry and sent me a bigger battery instead, I read their ratings and saw they also had a complaint about that battery, I asked him to have it tested before sending, which they never did or there would not be a problem. I had already had all the electrical equipment for the battery, now I had to get another bigger charger and casing total cost R750. Battery arrived the green indicator showed the battery fully charged I tested the battery was dead at 10.8V. I took it to specialist to check and charge he said no its dead rather send it back. I got back in touch with them and they said they would replace I must return the battery so I did in its original packaging, SAPO damaged package during transit they blame me. It takes a week to get a reply from them. They rather wanted to refund me, now they only refunded some of the money not what I paid for the battery and its return postage which is due. I'm still trying to get my money since 5 Sep. They are unprofessional.