I would add that them number of spokes is adding to the problem. If SamSam77 had 4 more spokes, those 4 extra spokes would share the load if one were to break. If it had 8 extra spokes, the stress on the other spokes if one breaks is even lower. One spokes weighs around 8g with the nipple. Four extra spokes weighs in at a whopping 28g but provides many times more strength.

I’d also add that going to a spoke with a heavier head like the DT Alpine III greatly increases the strength and durability of the spoke and, thus, the wheel at a minor weight penalty.

Although possible, a more likely reason for spoke loosening is poor spoke preparation during construction. Most machine built wheels I see have little to no thread locking on the spoke nipples which allows them to vibrate loose. Spoke nipple material may have an influence as well. Aluminum spoke nipples might not hold as tightly as brass does.

I would agree with taking the bike back especially for a new bike. However this will probably be only a lateral move. It will probably just be exchanging one problem for another. A longer term solution may be to build or have something built with better spokes.