Alloy wheel nuts

[N-Mir]

Hello, I have two nuts missing off my rear wheels one on each side, tried getting replacements preferably wheel locking nuts but nothing fits. I was told these were custom wheels and therefor cannot use stock nuts as they are too thick and the key wont fit in. The nuts I have are thin, Ive uploaded pictures of what are on it now and what I bought, the locking nuts are thicker just at the end that screws on the bolt otherwise they would have fitted but will be short in length as well. Been to local stores, halfords so on but no luck! Thanks