Contacting Organizations about Inaccessible Websites

[put comment here...]
My main problem is that some websites do not give any contact details.For example, I have been trying for some time to make a complaint about the websiteused by supermarket called Tesco. I cannot visit local store due to lockdown so I have to rely on online orders and deliveries. Nowhere in their website do they reveal their email address. Due to being disabled, I cannot use telephones. I have tried writing to theirhead office in Welwyn Garden City, Hertfordshire UK but they don't bother to reply to letters. Main problem as far as I am concerned is not having a telephone, I don'twant a telephone because I would not be able to use it if I did have one.Fortunately, before lockdown, me and my neighbours, who are all disabled,obtained funding to get a communal wi-fi installed, so I can send emails even thoughI have no telephone. It is absolutely disgraceful the way that so many websites are set up 
to discriminate against deaf people by being designed in such a way that "telephone number" is a mandatory field and not allowing people to send them emails through their website unless they give a telephone number. Direct emails are much better anyway because because that way a copy goes into "sent" folder and because attachments can be included if necessary.Unfortunately, there is no remedy because legal aid is not available for claims of 
disability discrimination unless the discrimintion relates to employment. 
D Gallant