Just keep wearing your old ones until the new one arrives...if pinged simply point out that you applied for renewal x mths ago and it hasn't arrived yet even though money was deducted from CC on y date.
They will not dare to make a huge issue and if by some stroke of luck you strike one who does just sit back, relax and let them wind themselves into a ball of stress...them actually delaying your flight would be an extra bonus...double bonus points if they delay you long enough to make it impossible to complete your rostered duty within legal FTLs.
When it gets to the part where your ability/right to earn a living has been restricted by their incompetence you watch them back down.