Car giving us issues within six months

We bought a car on 27 March 2021 from Citton Cars and we didn't purchase a warranty that time as we was told that should the car give us issues within six months we should bring it back. Now within that six months the car is disconnecting from the battery. Citton Cars has advised that we need to sort it out myself.

If we were told that the warranty that would cover the six months is ours, we would have made other plans.