Caravan for repair my rights

wolfman345Y

I took my caravan for its second service only to be told the back has a crack not my fault and 27% damp in front right side and needs to go back to sterling.  They arranged for it to be returned but not for 5 months then their keeping for 6-8 weeks.  What
rights do I have it's on finance and I'm being deprived of its use over Easter and last year I paid a £50 none refundable deposit for our Easter break.   Sterling say their not responsible for any lost booking as per their terms and conditions so not only
have I missed a prime holiday but I cannot book any alternative as they won't give a specific return date. And I'm paying for a caravan I cannot use for 6-8 weeks any advice be grateful.