我已经为您提供了20％的折扣，另外请您告诉我所选赠品的号码．

I've made a 20 percent discount for you. And would you please tell me the number of the offered free item?

I have already provided 20% discount for you, moreover asked you totell me to choose the complimentary gift the number

20% off we offered already for you ,please let me know what's a code of free item as a gift (or bonus) you would be selecting ?

我已经为您提供了20％的折扣，另外请您告诉我所选赠品的号码．
I have to offer you a 20 per cent discount, and you tell me the number of the selected gifts.

我已经为您提供了20％的折扣，另外请您告诉我所选赠品的号码．
I have offered you 20percent discount for you,in addition ,please let me know a code of the freebie you have selected.