OK, let me answer your question.
Not proud of it but I have worked in scam calling center for a while... obviously not knowing we were scamming people. It was a really elaborate one.
First thing. How did they got your number. Now, the first time you called the call center, which was certainly in India or a similar country recorded you number. This call center is legit company assisted. They are not allowed to record your number but they did.
Now, this legit call center gathered a thousand or so number and then sold them to a not very legit call center that scams people.
This call center has definitely a scene up their sleeves for people who were having difficulty with visits.
One you said you don't need a visit they had nothing to do with you. Their scheme probably targets people who haven't had their visit or are having difficulties still.