Vodacom useless as always

Wanted to cancel my data contract and was advised that due to me being a client for a long time they would like to keep me. They advised they would give me 15gb a month for R79. Just before of end of call stated that it is 10gb day and 5 gb night. Now first month they bill me R169 for 5gb day and 5gb night, called and advised that it is 5gb day and 5gb night and 5gb video that is a lie as on my previous accounts it show the 5gb video and this does not!! This is the last time that I use them as when I took out this contract advised I could use more than one sim that was lie as well. They advised me that I need a diffrent contract when I phoned to apply for extra sim!!!