Threats on missed payments

I have an account with OK furniture, I took the couches that were worth R15000 and total repayment is R30000 due interests and so forth. Last year in June I got retrenched, have since been unemployed and made impossible to keep up to date with all my accounts. So every time I miss an instalment, whenever I pay no money goes back to the principal it all goes to penalties, and penalties are 100% of monthly payment. I have missed instalments 7 times and now instead of paying what's due I also have to 7 times worth of penalties. In that period I was harrased and threatened that goods will be repossess if I don't make an immediate payment. They have attempted before and give my moher threats that if I don't pay arears, they will take the couches, because she is the one always at home. Often I'll try my best to make any minimal payment, though not working. What is said that money for rentrencment insurance kept is taken every and without me being told of this cover.