Car has idling problems

I bought a Toyota yaris from them in December 2019, I realised after collecting the vehicle that it did not have a Lic disc, the sales person advised me to get a permit and promised me that they will refund me, I have still to date not receivedy refund. Later realised that the car battery was not an original one, struggled to get them to replace the battery and now the idling of the car is not normal and I am not getting any help from them