Unlock iphone 5

Hello!

I am a fan of Apple products since 2011. In 2011, I bought an IPhone 4.

Then I had an iphone 5 64 gb.

This phone was given to me by my parents for my birthday!

When my parents bought it, they asked the seller to download several soft on it.

The seller, used his own Apple ID to activate phone and download some soft.

When I received the gift, I started to use my own Apple ID.

Then I bought new models of iphone. I didn’t use Iphone 5 for a long time, Soon I forgot the password to unlock, entered it incorrectly 3 times and then blocked my phone.

To recover it, I need a password from an apple id that was originally entered, but I do not know it. I can not find the seller.

I have a box from this phone with it own imei.

My apple id was used on this phone immediately after the purchase. In the history of purchases you can find this information.

I would be very grateful if you help me to unlock my phone. I do not want to throw it out.

Thank you!

P.S. Sorry for my English.