Poor Service - Pretoria Caravans

I purchased a new Sprite caravan last year on the 21st June, We were supposed to have the first service done 6months later. However we were out of the country. We returned for a few days after new year and then went overseas again until end of February. We have tried to take the caravan for the service now and been told we cannot and no longer have a guarantee. We have explained that the caravan has not been used and that we have been away. The response was rules are rules and they have to comply with their service policy. What were we supposed to do? Come back or plan our trips around the service of the caravan. When I purchased the caravan last year we had to go and collect the rod for the hanging cupboard and install it myself so where is the quality checks. This was not the only issue we had. I will not and strongly recommend people do not use Pretoria Caravans as they are not prepared to be reasonable. Once they have your money, their is no customer service