Phone service warranty/guarantee

I bought a vodacom smart kicks 2 phone at Pep store heugh Rd Walmer on the 16 September 2017. The phone went dead within a month. I returned the phone to the store and was told "the phone will go for repairs, if not I will be given a new phone" within 8 weeks.

Today I went to Pep store to check if the phone has arrived, the store manager or supervisor "Natasha" assisted me and apparently the phone was ready for collection. When she checked the phone box, she noticed that it's a new phone. So I noticed that there was no battery in the phone nor in the box. She then read what vodacom had written on the documentation attached to the box. It is written in black and white that " client need to replace the battery"

I fail to understand why I must buy a new battery, when this phone is still under warranty. I was never told that the warranty excludes the battery. If that's the case then I demand a FULL REFUND