Problem with Behringer XD80USB pad

Hello everyone,

about 2 months ago I bought the Behringer XD80USB drumset. For the first 2-3 weeks everything was completly fine and worked perfectly. But the I found out that the 'drumhead' of the snare pad going deeper to the pad and that caused that my sticks dont bounce of it that good, the response got worse and and when I hit it like really soft it makes the sound of a rimshot (I hit it in the middle not on the edge). At first I said to myself: "Well I'm not a jazz player so I don't mind if i can't do some light hits...". Another month passed, I turned on the kit, started playing and the snare drumhead was even more deeper and it was making that rimshot sound wherever I hit it.
Obviously I'm pretty upset about it, because I have this drumset for like 2 months like I said and really don't know what to do.
Thank you for any kind of help.
Have a great one out there folks!