Premiums tripped with no explanation and won't respond to my emails

I am currently in the UK and, as I haven't been able to get back to SA in almost two years thanks to Covid, have had to rely on trying to deal with Outsurance via email. In my absence, my son is taking care of my house and occasionally drives my car to and from the shops to keep it running. He was recently involved in a minor accident for which he was responsible. Due to my car's age and the limited damage, we decided not to have the repairs done through insurance due to the large excess. I need to point out that my son is 34 years old and therefore an experienced driver. I also need to point out that Outsurance were very quick to contact me, via email, when the claim arose and were insisting that my son be nominated as the insured and main driver. I refused the change as my son barely uses the vehicle except for the odd occasion to keep the battery running. I am still the owner of the vehicle and the policy holder as well as the main driver under ordinary circumstances ie before Covid kept me in the UK. My premiums, which were confirmed by Outsurance in December to be R929.49 have however tripled for the past 6 months or more and Outsurance has been deducting R3178.12 instead of the R929.49 every month with no explanation. I have tried to reach them on several email addresses and yet no response from Outsurance. I have even emailed to state that I want my policy cancelled if they continue to deduct these premiums and again, no response. I want a refund for the months that I've been overcharged and a full explanation as to why they have taken this money with no prior communication but getting Outsurance to respond to my emails is impossible and, as I am not able to use my SA cellphone, emails are my only way of corresponding with them. I want these deductions stopped and the additional money they've taken from me to be paid back.