Dell xps 15 9570 memory slot bad connection

Hey, I have a dell XPS 15 9570 for a bit over 2 years now but it is having problems with 1 of the memory slots. It looks like the connection is bad. I Have swapt the memory around and running on 1 slot. both of the sticks seem to be working good in the B slot but not in the a slot. I will randomly get the 2 amber 4 white error at boot and sometimes the screen freezes randomly when in use.

Can somebody help me out it is realy hard getting in touch with dell can't find a support mail anywhere on the website?