That's good news Watson! Words of encouragement. And you now know the range of cli's before you reach the end of them.
Who knows what they will follow up with? Yes, I'd say a phone call in April or May is justified.
And yes, that backdoor number is great to use. I NEVER use the number on the back of the card anymore, except maybe to check my balances. But I've not even done that in months since I'm signed up online with them.
And congrats on the cli! Good job.