Wefix Menlyn poor service

On the 2nd of December 2018 I took in my iPhone 6 black in for screen replacement in Menlyn store, on my mind I was like the battery will also be replacement as according to the deal I saw on the wefix website. later on the 2nd I got an sms that my phone is ready for collection. so went to collect the phone on the 3rd of December, when I got I realized the battery was not replaced, I tried to call the store got no answer, the following day I called several times but still no answer, today I was able to get hold of the store, I ask them why my battery wasn't replaced as according to the deal on the website, the lady who answered my call get to tell me that I was suppose to request battery replacement as while now these nothing they can do as I have already collected the phone, how on earth should I knew I was suppose to request it, as no one even asked if my I would need a battery replacement or not, and as repair specialists couldn't the see the battery needs replacement?