Arrangement refused, all I'm told is my car will be repossessed!

I only learnt today that I had accumulated arrears on my car payments and the major cause is them not communicating with me prior instead they handed me over to people who refused to make arrangements all they do is telling me they will reposses my car after I've paid it for almost 3 years, mind you the arrears they caused because they never advised me they HAVE added their own insurance from June this year. Today I try to make an arrangement they are sending me from pillar to post. I won't lie I'm so disappointed I mean now I'm forced to pay a premium of 5700 + 5780 arrears where will I get such? All I asked is to make arrangement to atheist pay arrears in terms.