At first, I suggest to you to remove the battery and to take note about your IMEI.
And then, I suggest you to try to solve this issue with "Mobileuncle MTK Tools" apk.
Install "Mobileuncle MTK Tools" apk ... Tap Engineer Mode ... tap Engineer Mode (MTK) ... tap Connectivity ... tap CDS Information ... tap Radio Information ... tap Phone ... and in line AT +EGMR=1,7,"IMEI_1" (replace IMEI_1 with the imei written on the back of your device) ... YOU MUST ENTER SPACE BETWEEN AT and +, so not AT+EG but AT +EG ... tap on SEND AT COMMAND ... quit Mobileuncle and reboot your device.
:-)
And then, I suggest you to try to solve this issue with "Mobileuncle MTK Tools" apk.
Install "Mobileuncle MTK Tools" apk ... Tap Engineer Mode ... tap Engineer Mode (MTK) ... tap Connectivity ... tap CDS Information ... tap Radio Information ... tap Phone ... and in line AT +EGMR=1,7,"IMEI_1" (replace IMEI_1 with the imei written on the back of your device) ... YOU MUST ENTER SPACE BETWEEN AT and +, so not AT+EG but AT +EG ... tap on SEND AT COMMAND ... quit Mobileuncle and reboot your device.
:-)