The Residential Tenancy Act (RTA) does NOT apply when a renter shares either the kitchen or bathroom with the owner of the property. This includes homestays.
It is important to note that the RTA may apply if you are sharing a kitchen or bathroom with a landlord who is not the owner of the property. For example, if a tenant rents an entire house, and then rents out individual rooms to other tenants, the original tenant is usually considered the landlord of the other tenants. Situations where one tenant is renting rooms and collecting rent from other tenants can be complicated, and if disputes arise it will be up to the Residential Tenancy Branch to decide whether or not the RTA applies.
You may be able to resolve your issue in court, or use an independent mediation service, such as Mediate BC. There is a fee to use Mediate BC, but it will likely be lower than court or lawyer fees.