Do you have a second contract?
14,99€ is the price for a second contract with the tariff o2 Free M (called “Partnerkarte”; 50% discount included.) If you have only one contract, the Free M costs 29,99€ (Free M FLEX costs 34,99€)
No, it's my first contract, there is no option for Free M though. Only the ones that i shared. I just want to lower tariff because I don't need that much any more.
Hi @mertcangurcan,
welcome to our English Community. 
I regret that I could not contact you earlier. But now I am there for you.
Unfortunately, an extension into the tariff “o2 Free M” with 24 months duration is not possible.
But as you have a cancellation period of 1 month, why not ordering a new tariff. But please keep in mind that you will get a new mobile phone number. Your old number is not transferable to your new tariff.
What do you think about this alternative?
If you like I can send you an offer by e-mail.
Loving greetings,
Tobias
Hello, please my data plan is O2 free S 3Gb online, is it possible to switch to O2 free M 20 Gb online? If yes how do I go about it because I need more data ?
Hello @zaak1,
thank you for your request in our community!
Do you want to actively extend your contract and thus change to a larger contract or do you want to change the contract during your term? Is your contract renewable yet?
If you renew your contract, you may receive a new offer with new discounts. However, if you change your tariff during the contract period, your current discounts will no longer apply and you will pay the normal basic tariff fee.
All information according that topic you can find here:
Kind regards
Jessica 
Hello @zaak1,
thank you for your request in our community!
Do you want to actively extend your contract and thus change to a larger contract or do you want to change the contract during your term? Is your contract renewable yet?
If you renew your contract, you may receive a new offer with new discounts. However, if you change your tariff during the contract period, your current discounts will no longer apply and you will pay the normal basic tariff fee.
All information according that topic you can find here:
Kind regards
Jessica
Thank you. Please I have almost 13 months more to end my contract but I want to upgrade to O2 free M 20 Gb online on the same contract. Thank you
Hello @zaak1,
we will send you the offer for your tarif change within a few days via email. Therefore, please check if we have a current email address for you.
Please see our product information sheets for further details. Note that the prices contained therein are standard prices excluding any discounts.
Best regards
Giulia
Hello @zaak1,
i have send you an offer for changing your Tarif without extension of the term. When you need a further offer, please contect us in this thread.
Best regards, Marco
Thank you, just what I needed
Hallo @zaak1,
its nice to read that. 
When you need further information or an other help, please write us here.
You are always welcome.
Best regards, Marco
