Misleading summer gigs

Your promo summer gigs is a great initiative but you not abiding to your ad of giving "get your 100% data back the next day "you know at times you don't get it all which is misleading to your customers. I called your customer service a few times to understand this concept but was told you get 10% of your data which you used back the other time I was told that the network decides what data you get and obviously what you used.Now please let me understand this because this is very misleading.The law is nobody gives you something for nothing and especially in business.