My connection is so bad and any minute i lost connection

Bad connection 

Perhaps start by checking coverage locally:  https://smarty.co.uk/coverage-checker?_gl=1*ubyquu*_ga*NDQ3NjAxODQyLjE2NzY5NjgyMDE.*_ga_D8LNLN41LX*MTY4MDM1Nzc2OC4xMTIuMS4xNjgwMzU5MzI2LjAuMC4w

Is the problem the same wherever you are? If so, can you try the sim in another phone? Maybe also worth giving the sim a gentle clean and put back into phone.

I'm sorry to hear this, federic_1195840 

Please follow the steps provided below to reset your network settings, this may boost your signal but it is not guaranteed:

•   Restarting your device and/or resetting your Network Settings (this does not affect your device storage, apps, pictures, etc.). This will refresh your connection to the serving site, prompting a stronger signal.

•    Toggling Airplane Mode/Mobile Data off and on. This essentially resets the IP connection, establishing a fresh new connection once linked to the network – this will prompt your device and SIM to connect to a stronger signal.

•     You can remove any saved APN credentials, restart your handset and then re-add the required APN if your device doesn’t seem to automatically connect to a strong network signal – please find

guidance on the correct APN set-up via the following link: https://help.smarty.co.uk/en/articles/1155220-using-the-internet-after-you-ve-joined-smarty.