It is important to be aware of sub-contracting carried out by your provider as this could affect the location of your data and your access rights. If you are unsure or not able to be specific about who holds your data and where they are, it could also create issues under GDPR or other regulations.
Suspension and termination rights and exit assistance
Irrespective of how termination is effected, you should ensure that you have a suitable run-off period at the end of the contract (i.e. continued service provision for a reasonable period subject to the payment of fees). This will provide you with a period of continuity until you set up a new system, even if you breach the contract, and time to recover and migrate your data.