DONT is really, really horrendous against a mini-NT, or even a weak NT. You really need to have some sort of system with a Penalty X. My recommendation is a slightly modified HELLO: X = Penalty (Doesn't need to be balanced, or have a ton of high cards, Just a hand with 7+ defensive tricks) 2♣ = Relay to 2♦, Shows ♦ or a M/m (With the M/m you bid the M over 2♦, then 2N by partner asks for the minor] 2♦ = Hearts 2♥ = Both Majors 2♠ = Spades 2NT = Clubs or Near-GF in ♦/♥/♠ (The strong variant is shown by bidding a new suit once partner bids 3♣ 3♣ = Minors 3♦ = Both Majors, strong (e.g. partner should bid game in the desired strain with 1.5 tricks or so...or even no tricks and 4+ in a M) 3M = Preemptive but sound (e.g. willing to play 3Mx opposite shortness)