Can I unblock a phone that has been blocked?

I have an iphone 6s, wasn't able to pay off the bill cus I was forced to leave my job for health reasons
The bill kept piling up and I now owe around £1,200
The network provider vodafone blocked the sim/phone as my phone now says No Service and I can't receive calls and texts or send them (so it is like an iPod now basically)

I'm paying off the bill a few pounds a month and it will take years to pay the whole thing off (don't have any other option such as loans)

If I took it to a repair store, is it possible to unblock/unlock this phone to receive calls/texts? I'd put in another sim. The phone is on a contract with voda so I just want advice.

(Had to mention every detail as some people question instead of answer)

That is not possible, only the ones who blacklisted it can unblock it. You'd have to pay it off before you can get it unlocked

No if the provider has locked it. The imei will not work, it's been disabled. You

now have a useless piece of plastic.

The SIM isn't blocked, it's the phone itself.

No, you can't

Until Vodafone unblocks it it Can't be used as a reqular cell phone
BUT BUT try this. See if you can get a Wi-Fi signal (Internet) even a blocked phone with NO service can sometimes access the Internet.
If you can there are companies that allow you to make and receive FREE phone calls and messages via the Internet.

Text Free
Dingtone

They will put in ads but they are FREE. And you can make and receive calls and text.