Erm, no, it's a bit more complex than that.
The DSR requires some information to be given prior to the conclusion of the contract, but other bits can be given later .... though not much later.
Info about liability for the cost of return goods is in the latter category, and must be given
If they aren't, then the way the DSR rates changes a bit, most notably the usual "with 7 working days" can be a LOT longer than than, such as 7 days from when you do get told, or 3 months and 7 days if you aren't told.
The DSR also specifies methods of communication. It's really best to read it, though, rather than me trying to reinterpret the whole lot, because that bit is more or less a list.
This is a link to the first category of required info, and the "next

rovision" button at the bottom takes you to bit about returns info.
As fpr the phone, no. The info has to be in provided "... to the consumer in writing, or in another
durable medium which is available and accessible to the consumer, the information referred to in paragraph (2), ...."
Phone calls aren't "durable". It's broadly phrased to give maximum latitude for method of communication, but would cover letter, fax, email, presumably SMS, etc, but not phone, and I would also say they are taking a chance if they just say the T&Cs are on a web page somewhere, 'cos the DSR doesn't say "make available, however obscurely", it says "provide to".
Hence, from any decent company,
every transaction comes with a confirmation mail/message with a whole load of blurb 99.99% of people don't read.
