Audio Systems: car amplifier cuttin off, car amplifier, panel speakers

Question
I got a brand new kicker zx1500.1 amp hook up to 2 kicker 12sl7 a few weeks ago .I have 2 battaries and a cap to go with this system. The problem is that when i turn up the volume to 22 the music playin on the woofers cuts off unless i lower the volume to 13 while the front panel speakers and the rear panel speakers still keep on playin this are hook up to another amp. I took my car back to the shop that install the amp right in the spot it looks like they fix the problem but a day later the problem is back can you please advice me on what is the cause of this  problem should i send the amp back so it can get replace or is a bad installation?  

Answer
there are 2 versions of these subs,  there is the S12L72 and the S12L74.  depending on which one you got, the ohms will be wrong for this amp and cause it to be overloaded and shut off.
Specifically if you have the 12SL72 and all coils are wired in pararllel you would overload the amp.

check which speakers you have if you can see the model number on them or if you have a box or recipt.  
If you do have the 12SL72 and YOU picked them out then its basically your fault not the installers,  they should've told you that it was a bad match but oh well.  if you paid them to design your system and they matched it up like this then demand they swap the 12SL72 for the 12SL74 which is the correct match for this amp.
If you do in fact have the 12SL74 and this problem is happening, let me know, something else must be wrong.
Good luck!