Epic & Legendary Coin Purse purchase bug

There is an issue with hearthstone mercenaries purchases. Recently I’ve purchased Epic Coin Purse where it states I’d get 200 coins for 3 random epic mercenaries however that did not happen. I’ve been awarded with only 2. 200 for Tirion Fordring and 200 for War Master Voone. No 3rd coin.

This has also occurred 1 more time before when there was 3x250 coins promotion. Same thing happened and I was given 2x250 instead of 3x250 coins. I’ve checked multiple times.