Short and Sweet! 

Product's you would like to exchange, simply get in contact and give me a head's up and as long as these are unused and in the packet I will exchange no problem :)  

In regard to any issues with order's you receive, I have in place something that cover's both you and me.

Here at the office a record of what is sent is kept and on the front of your parcel you will have a number with what you've received. A screen shot of this should be added to any message sent with queries.