Battery Base - Brickfield Road :(

So last year around April we purchased a battery from Battery Base in Overport. After about 8 months of usage the battery starting giving us problems. It would not want to start and my husband had to get someone to boost the battery. Every time we take it back to the shop we are given a loan battery and they charge the battery which we have purchased. This is going on way to long now as the guarantee is almost up and they do not want to give us a new battery. Yesterday again the car could not start and when my husband went to the shop they said they do not have a battery to lend us. How long are we going to suffer like this as it seems you are waiting for the guarantee to expire then we will be out of your face.