If you do not feel as though you are capable of following the instructions given by Kanewolf to safely update the BIOS yourself, then it is likely in most regions you can take the system to a systems builder or repair facility and for a small fee, have them update the BIOS for you. You will want to be sure to take it to a REPUTABLE technician or repair facility, because allowing in any damn fool yahoo out there who says "I know how to work on computers" could easily result in bricking the motherboard the same as you doing it could.
That being said, it's really not rocket science. If you follow the steps given by Kanewolf AND take the time to read any instructions on the motherboard product page including any related to updating the BIOS, and perhaps also watch one or two videos on updating the BIOS on Gigabyte motherboards, you should be fine. If you don't feel confident enough after doing that, then take it to somebody who can do it for you.
Either that, or return that memory kit, then order a two DIMM memory kit that adds up to the quantity of memory you wish to run, rather than trying to run four DIMMs, and make sure it is a memory kit model that is either listed by the memory manufacturer as compatible with that board or is listed on the motherboard QVL list as compatible, and then sell you existing kit.
Truthfully, you'd be much better off trying to run a 2 x8GB kit of 3200mhz sticks than attempting to run 4 x4GB, especially when two of the DIMMs did not come with the other two and you have no idea if they will EVER work together or not.